Check out the Space Time Merch Store null In 1974 we sent the Arecibo radio message towards Messier 13, a globular cluster near the edge of the Milky Way, made up of a few hundred thousand stars. The message was mostly symbolic; we weren’t really expecting a reply. Yet surely other civilisations out there are doing the same thing. So, why haven’t we heard anything? What if the silence from the stars is a hint that we shouldn’t be so outgoing? What if aliens are deliberately keeping quiet for fear that they might be destroyed? Sign Up on Patreon to get access to the Space Time Discord! https://www.patreon.com/pbsspacetime PBS Member Stations rely on viewers like you. To support your local station, go to:http://to.pbs.org/DonateSPACE Sign up for the mailing list to get episode notifications and hear special announcements! https://mailchi.mp/1a6eb8f2717d/spacetime Search the Entire Space Time Library Here: https://search.pbsspacetime.com/ Hosted by Matt O'Dowd Written by Richard Dyer & Matt O'Dowd Post Production by Leonardo Scholzer, Yago Ballarini & Stephanie Faria Directed by Andrew Kornhaber Associate Producer: Bahar Gholipour Executive Producers: Eric Brown & Andrew Kornhaber Executive in Charge for PBS: Maribel Lopez Director of Programming for PBS: Gabrielle Ewing Assistant Director of Programming for PBS: John Campbell Spacetime is a production of Kornhaber Brown for PBS Digital Studios. This program is produced by Kornhaber Brown, which is solely responsible for its content. © 2024 PBS. All rights reserved. End Credits Music by J.R.S. Schattenberg: null Space Time Was Made Possible In Part By: Big Bang Sponsors John Sronce Bryce Fort Peter Barrett David Neumann Alexander Tamas Morgan Hough Juan Benet Vinnie Falco Mark Rosenthal Quasar Sponsors Glenn Sugden Alex Kern Ethan Cohen Stephen Wilcox Mark Heising Hypernova Sponsors Chris Webb David Giltinan Ivari Tölp Kenneth See Gregory Forfa drollere Bradley Voorhees Scott Gorlick Paul Stehr-Green Ben Delo Scott Gray Антон Кочков Robert Ilardi John R. Slavik Mathew Donal Botkin Edmund Fokschaner chuck zegar Jordan Young Daniel Muzquiz Gamma Ray Burst Sponsors Jessica M. Kandal, Ph.D. Anthony Crossland Grace Seraph Frank Plessers Max Paladino Stephen Saslow Robert DeChellis Tomaz Lovsin Anthony Leon Leonardo Schulthais Senna Lori Ferris Dennis Van Hoof Koen Wilde Nicolas Katsantonis Joe Pavlovic Justin Lloyd Chuck Lukaszewski Andrea Galvagni Jerry Thomas Nikhil Sharma John Anderson Bradley Ulis Craig Falls Kane Holbrook Ross Story teng guo Harsh Khandhadia Michael Lev Terje Vold James Trimmier Jeremy Soller Paul Wood Joe Moreira Kent Durham jim bartosh John H. Austin, Jr. Diana S Faraz Khan Almog Cohen Daniel Jennings Russ Creech Jeremy Reed David Johnston Michael Barton Isaac Suttell Oliver Flanagan Bleys Goodson Mark Delagasse Mark Daniel Cohen Shane Calimlim Tybie Fitzhugh Eric Kiebler Craig Stonaha Frederic Simon Tonyface John Robinson Jim Hudson David Barnholdt John Funai Adrien Molyneux Bradley Jenkins Amy Hickman Vlad Shipulin Thomas Dougherty King Zeckendorff Dan Warren Joseph Salomone Patrick Sutton Julien Dubois